That's because while Facebook was struggling to build mobile apps based on HTML5, a language used to build desktop websites, Path was building smartly designed native apps running on Apple and Google's mobile operating systems.

So how exactly does Zuckerberg want to work more closely with Morin?

We don't know, but at TechCrunch Disrupt, Zuckerberg described how Facebook's deal to buy Instagram came together. First, he and Instagram CEO Kevin Systrom sat down and talked about all of the ways they could work together and integrate their products more closely.

Then they realized that it would be hard for Instagram to justify committing so much time and energy to Facebook, and vice versa, unless they were part of the same company.

So maybe, just maybe, there's a chance Zuckerberg ends up buying Path somewhere down the road.